Cecilia Reyes, center, the mother of an unarmed National Guardsman who was fatally shot during a traffic stop, at a press conference Thursday.

The Queens District Attorney on Thursday told the mother of an unarmed motorist who was fatally shot last week by a New York City Police detective that a grand jury will likely be convened to determine if any criminal charges should be filed.

In a 30-minute meeting with Cecilia Reyes and her two attorneys, District Attorney Richard Brown “advised us that it is likely that a grand jury will hear this case” in the shooting death of National Guardsman Noel Polanco, attorney Sanford Rubenstein said.

In a statement, Brown said while the investigation is in its early stages, “I told [Polanco’s family] that when we conclude our investigation I expect that we will present all of the facts to the grand jury.”

A law-enforcement official said that this is the most delicate investigation involving an NYPD shooting in Queens since Sean Bell was shot and killed by police the night before his wedding in 2006.

Not all police-involved shootings go to a grand jury, and there is no time frame for when a decision will be made to convene a grand jury.

“All I want is justice. I don’t want this to be repeated for anyone, and I just want this to be done the right way,” Reyes said. “They are really going to work on this, they are going to investigate this and I have faith that they are going to do this.”

Speaking to reporters Thursday after an event, NYPD commissioner Raymond Kelly reiterated his belief that the shooting, which occurred during a traffic stop near LaGuardia Airport last week, will have to be presented to a grand jury.

“Not every case goes before the grand jury,” he said. “I believe that this case has to go before the grand jury.”

Polanco, 22 years old, was shot once in the abdomen by Det. Hassan Hamdy, 39, after police pulled him over for driving erratically, officials have said.

Hamdy’s attorney, Philip Karasyk, has said his client saw Polanco “lunge” toward something under his seat and believed “he was about to be met with deadly force,” when he fired the fatal shot. Hamdy looks forward to telling a grand jury his version of events, Karasyk said.

A funeral for Polanco is scheduled for 10 a.m. Friday at Eternal Love Baptist Church in Corona, Queens. The Rev. Al Sharpton will deliver remarks.

“He was a great child. I never had any problems with him. He was just a beautiful child,” Reyes said. “I guess no mother is ready to say good bye to a child. It’s hard. I don’t know how I am going to handle this.”

Corrections & Amplifications: A photo caption in an earlier version of this post misstated the surname of Cecilia Reyes, the mother of National Guardsman Noel Polanco.